Okay, I went back and looked. The pic of Deidre/Freddie was posted on Oct. 9. So if she posted it when she took it, it could be for scenes after the wedding easily. But she posted some pics from the Christmas episode a good six weeks after they filmed it.

What made us think Deidre was in the 12,000th episode originally was all those videos she posted talking to different actors about it. I can't find those videos now. So some time around the time they filmed the 12,000th, Joe Mascolo, John Aniston, and Deidre were on set.